Animal Rights groups have taken on trainers who worked on ‘Water for Elephants,’ ‘Zookeeper’ for a giraffe’s death and ‘The Hangover Part II’ for not using monitors and depicting a monkey smoking.

At the premiere of “Rise of the Planet of the Apes” a clutch of impassioned animal activists gathered on Hollywood Boulevard. But they weren’t there to throw red paint on fur-coat-wearing celebrities. Instead, one demonstrator — dressed in a full-body monkey suit — had arrived with a sign complimenting the filmmakers: “Thanks for not using real apes!”

With a computer-generated tiger at the center of the upcoming “Life of Pi” a controversy over live animals is brewing on a different holiday release.

Wranglers in New Zealand have complained that as many as 27 animals have died as a result of conditions away from the set of “The Hobbit: An Unexpected Journey” according to the Associated Press.

The creative team behind “Apes” used motion-capture technology to create digitalized primates, spending tens of millions of dollars on technology that records an actor’s performance and later layers it with computer graphics to create a final image — in this case, one of a realistic-looking ape.

“There are some performing animals that actually do have a more fulfilling life, but apes, you could probably say that’s not the case,” director Rupert Wyatt said. “In order to do what we need to do with them [in the film], you’d need to dominate and exploit them. I’d like to think that hopefully with performance-capture, we can bypass that and keep apes in the wild.”

Yet “Apes” is more exception than the rule — in fact, Hollywood has been hot on live animals lately: The nonprofit American Humane Assn., which monitors the treatment of animals in filmed entertainment, is keeping tabs on more than 2,000 productions this year, 100 more than in 2010. Already, a number of high-profile 2011 films, including “Water for Elephants,” “The Hangover Part II” and “Zookeeper,” have drawn the ire of activists who say the creatures featured in them haven’t been treated properly.

In some cases, it’s not so much the treatment of the animals on set that has activists worried; it’s the off-set training and living conditions that are raising concerns. And there are questions about U.S. films made overseas, which sometimes are not monitored as closely as productions filmed stateside.

“I think it’s very disturbing, the trend that we’re seeing of more and more animals appearing in movies, and I think we should be moving in the other direction with the technology we have,” said Matt Rossell, campaigns director for the U.S. branch of ADI, a nonprofit group. “We’re calling on these studios to really take a good, hard look” at their use of animals in fictional entertainment.